PhD Study : Wastewater sludge to hydrogen via direct biogenic electrolysis

Summary

Wastewater sludge is the by-product of wastewater treatment plants. Currently, 13.5 million tonnes of dry sludge are produced in Europe annually, 1.5 million tonnes in the UK, and further increase has been projected with population growth. Sludge management poses several challenges due to its high liquid-to-solid ratio, which requires thickening and mechanical dewatering and the presence of toxic and environmental pollution compounds. However, sewage sludge is also an interesting feedstock for energy production due to its high organic content. Nevertheless, the sewage sludge environmental impact when not correctly disposed of, the unsustainability of current disposal techniques (like landfilling, storage, and composting), and the health concern towards some of its components for agriculture applications such as fertilisers make it necessary to rethink sludge management in a more sustainable and circular economy framework.

The present research focuses on producing hydrogen from sewage sludge from direct biomass electrolysis. Hydrogen has been defined as a critical fuel to decarbonise the UK and the EU energy sectors by 2050. Therefore, advancement in direct biomass electrolysis for hydrogen production from sludge is of interest to the water and energy industry. Direct biomass electrolysis can produce hydrogen from biogenic content, like biomass and biowaste.

Although the TRL of direct biomass electrolysis is still low (1-3), it has key advantages compared to existing technologies:

i) potential high yield of hydrogen (e.g. 0.2 mg of H2 for 1 mg of wasted raw material -Hibino et al., 2018; 15.76 mL hydrogen at a constant current density of 40mA/cm2 after 1 hour from 0.2 gram of corn straw powder- Liu et al., 2016)

ii) low energy demand of about 0.69 kWh per m3 of hydrogen (17% of the energy required by water electrolysis) (Liu et. Al., 2016);

iii) small treatment device footprint;

iv) limited requirement for waste pre-treatment, compared to pyrolysis and gasification;

v) little or no post-treatment requirement for the gas produced (e.g., hydrogen separation, purification).

Furthermore, the CO2 produced at the anode is ready to be used and captured (Chen et al., 2019).

The PhD student will:

*Develop an in-depth literature review of the state of the art of electrochemical technologies, with a focus on direct biomass electrolysis to produce hydrogen from sewage sludge

*Process modelling *Run a series of experiments using an electrolysis system and real wastewater sludge to assess the potential hydrogen production from sewage sludge and the main parameters influencing the reactions

*Model validation

*Case study analysis to assess the techno-environmental performance of the system for wastewater facilities compared with other existing technologies

Essential criteria

Applicants should hold, or expect to obtain, a First or Upper Second Class Honours Degree in a subject relevant to the proposed area of study.

We may also consider applications from those who hold equivalent qualifications, for example, a Lower Second Class Honours Degree plus a Master’s Degree with Distinction.

In exceptional circumstances, the University may consider a portfolio of evidence from applicants who have appropriate professional experience which is equivalent to the learning outcomes of an Honours degree in lieu of academic qualifications.

• Clearly defined research proposal detailing background, research questions, aims and methodology

Funding and eligibility

The University offers the following levels of support:

Vice Chancellors Research Studentship (VCRS)

The following scholarship options are available to applicants worldwide:

• Full Award: (full-time tuition fees + £19,000 (tbc))
• Part Award: (full-time tuition fees + £9,500)
• Fees Only Award: (full-time tuition fees)

These scholarships will cover full-time PhD tuition fees for three years (subject to satisfactory academic performance) and will provide a £900 per annum research training support grant (RTSG) to help support the PhD researcher.

Applicants who already hold a doctoral degree or who have been registered on a programme of research leading to the award of a doctoral degree on a full-time basis for more than one year (or part-time equivalent) are NOT eligible to apply for an award.

Please note: you will automatically be entered into the competition for the Full Award, unless you state otherwise in your application.

Department for the Economy (DFE)

The scholarship will cover tuition fees at the Home rate and a maintenance allowance of £19,000 (tbc) per annum for three years (subject to satisfactory academic performance).

This scholarship also comes with £900 per annum for three years as a research training support grant (RTSG) allocation to help support the PhD researcher.

• Candidates with pre-settled or settled status under the EU Settlement Scheme, who also satisfy a three year residency requirement in the UK prior to the start of the course for which a Studentship is held MAY receive a Studentship covering fees and maintenance.
• Republic of Ireland (ROI) nationals who satisfy three years’ residency in the UK prior to the start of the course MAY receive a Studentship covering fees and maintenance (ROI nationals don’t need to have pre-settled or settled status under the EU Settlement Scheme to qualify).
• Other non-ROI EU applicants are ‘International’ are not eligible for this source of funding.
• Applicants who already hold a doctoral degree or who have been registered on a programme of research leading to the award of a doctoral degree on a full-time basis for more than one year (or part-time equivalent) are NOT eligible to apply for an award.

Due consideration should be given to financing your studies. Further information on cost of living